Mapping the relationships between different dog breeds is rough (get it?), but a team of scientists at the National Institutes of Health did just that using the DNA of 1,346 dogs from 161 breeds. Their analysis, which appears April 25 in Cell Reports, offers a lot to chew on.

Here are five key findings from the work:

Dogs were bred for specific jobs, and this shows in their genes.
As human lifestyles shifted from hunting and gathering to herding to agriculture and finally urbanization, humans bred dogs (Canis familiaris) accordingly. Then over the last 200 years, more and more breeds emerged within those categories. Humans crossed breeds to create hybrids based on appearance and temperament, and those hybrids eventually became new breeds.

DNA from hybrid dogs backs up historical records.
Genetic backtracking indicates that, for example, mixing between bulldogs and terriers traces back to Ireland between 1860 and 1870. That timeframe and location coincides with historical records indicating a dog-fighting fad that’s linked with crossing breeds to make better fighters.

Geography also matters.
While herder dog breeds showed a lot of genetic diversity, they fall into two general groups from the rural United Kingdom and the Mediterranean on the breed family tree. When humans switched from hunting to farming, herding breeds may have emerged independently in different areas. Geography could also explain why these two groups use different herding tactics.

New World dogs aren’t all immigrants.
A genetic legacy of America’s early canine inhabitants lives on in some of today’s breeds. Dogs trekked to the Americas from Asia with people more than 10,000 years ago, but when European groups started to colonize the Americas, they brought European dog breeds with them. Past studies suggest that outside breeds largely replaced New World dogs, but the new dataset shows New World dog DNA actually does persist in a few modern New World breeds, such as Chihuahuas.

Big dogs evolved independently to be big.
European mastiffs and Mediterranean sheepdogs don’t share recent changes in their DNA, meaning their size traits arose separately and for different reasons. While both breed groups specialize in guarding things, mastiffs use their size to intimidate humans, while sheepdogs use their size to overpower animal predators. Larger size may have been one of the first traits that human breeders zeroed in on, the researchers suspect.

A wearable robot could prevent future falls among those prone to stumbles.

The new exoskeleton packs motors on a user’s hips and can sense blips in balance. In a small trial, the pelvic robot performed well in sensing and averting wearers’ slips, researchers report May 11 in Scientific Reports.

Exoskeletons have the potential to help stroke victims and people with spinal cord injuries walk again (SN: 11/16/13, p. 22) — and even kick soccer goals (SN Online: 6/12/14). But this new model focuses on a more ordinary aspect of the human condition: falling on your face or your rear. “Exoskeletons could really help in this case,” says study coauthor Silvestro Micera, an engineer at École Polytechnique Fédérale de Lausanne in Switzerland.
Most exoskeletons guide the movement of the wearer, forcing the person to walk in a particular way. But the new pelvic device allows the user to walk normally and reacts only when it needs to. A computer algorithm measures changes in a wearer’s hip joint angles to detect the altered posture that goes along with slipping. The robot then uses its motors to push the hips back into their natural position to, hopefully, prevent a fall.

At a rehab facility in Florence, eight elderly people and two amputees — two groups at risk for balance issues — tried out the device while walking on a treadmill. The robot picked up on slips within 0.35 seconds of a change of gait.

Still, the device has some hurdles ahead. The exoskeleton is bulky, so Micera and his team are working on a sleeker model that would be less imposing for elderly users. The team is also testing the robot’s skills in other types of balance loss like tripping.

When my girls were newborns, I spent a lot of time damp. Fluids were everywhere, some worse than others. One of the main contributors was milk, which, in various stages of digestion, came back to haunt me in a sloppy trail down my back.

I was sometimes alarmed at the volume of fluid that came flying out of my tiny babies. And I remember asking our pediatrician if it was a problem. We were lucky in that the amount and frequency of the regurgitations didn’t seem to signal trouble.

But some babies spit up a lot more, and seem to be in distress while doing so. That’s led doctors to prescribe antacids to treat reflux disease in these infants. A U.S.-based survey found that from 2000 to 2003, infant use of a type of antacid called proton-pump inhibitors quadrupled.

Those numbers point to worried doctors and parents who want to help babies feel better. The problem, though, is that antacids come with side effects. Mucking with acid levels can affect the body beyond the stomach, and these unintended effects may be even more meddlesome in babies.

“What we found in adults and what we’re starting to see more in children is that [the drugs] are not as benign as we used to think,” says U.S. Air Force Captain Laura Malchodi, a pediatrician at Walter Reed National Military Medical Center in Bethesda, Md.

Infants who took proton-pump inhibitors, a class of drugs that includes Prilosec and Nexium, in their first six months of life broke more bones over the next several years than children who didn’t receive the drugs. That example comes from research Malchodi presented May 7 at the 2017 Pediatric Academic Societies Meeting in San Francisco.

Malchodi and her colleagues examined medical records of nearly 900,000 healthy children. Of those, about 7,000 were prescribed proton-pump inhibitors by the time they were 6 months old. About 67,000 were prescribed histamine H2-blocking drugs, such as Zantac or Pepcid, and about 11,000 babies were prescribed both types of drugs.
Children who had received proton-pump inhibitors, either alone or in combination with a histamine H2-blocker, had more fractures over the next five years than children who weren’t prescribed that type of drug. The researchers tried to rule out other differences between the groups of babies that might explain the higher number of fractures. When those differences were removed from the analysis, proton-pump inhibitor prescriptions were still linked to fractures.

The study can’t say whether proton-pump inhibitors definitely caused weaker bones. But that’s not an unreasonable hypothesis given what’s seen in adults, for whom the link between long-term use of proton-pump inhibitors and broken bones is stronger.

If proton-pump inhibitors do interfere with bones, it’s still a mystery exactly how. One idea was that the drugs hinder calcium absorption, leading to weaker bones. That idea has fallen out of favor, Malchodi says. Another proposal centers on cells called osteoclasts. To do their job, these cells rely on proton pumps to create acidic pockets around bones. But if osteoclasts aren’t working properly, “in the end, what you get is disorganized bone,” Malchodi says.

Reflux disease is not the same thing as reflux, which babies are nearly guaranteed to experience. For one thing, the amount of liquid they’re slurping down relative to their body weight is huge. And that liquid is held down by an esophageal sphincter that’s often underdeveloped in babies. (One technical term for reflux is “poor gastric compliance,” but I bet you’ve got more colorful descriptions.)

Antacids won’t stop babies from spitting up, says Malchodi. “We definitely counsel parents all the time that this is not going to stop the reflux,” she says. Instead, the drugs are thought to change the pH of the liquid coming back up in an attempt to make it less irritating.

Some babies may need that pharmaceutical help. But many may not. If babies are growing well and don’t seem to be in long-lasting distress, then it’s possible that they may need the “tincture of time” to outgrow the reflux. (Malchodi points out that so-called “happy spitters” are probably not smiling while they’re barfing, because obviously, throwing up is not fun. It’s just that these babies don’t seem to be bothered long after the spitting.)

She hopes that her research and other studies like it will prompt more careful discussions between parents and doctors before antacids are prescribed. And if they are deemed necessary, “have a stop point in mind,” she says.

For centuries, skywatchers have reported seeing and simultaneously hearing meteors whizzing overhead, which doesn’t make sense given that light travels roughly 800,000 times as fast as sound. Now scientists say they have a potential explanation for the paradox.

The sound waves aren’t coming from the meteor itself, atmospheric scientists Michael Kelley of Cornell University and Colin Price of Tel Aviv University propose April 16 in Geophysical Research Letters. As the leading edge of the falling space rock vaporizes, it becomes electrically charged. The charged head produces an electric field, which yields an electric current that blasts radio waves toward the ground. As a type of electromagnetic radiation, radio waves travel at the speed of light and can interact with metal objects near the ground, generating a whistling sound that people can hear.

Just 0.1 percent of the radio wave energy needs to be converted into sound for the noise to be audible as the meteor zips by, the researchers estimate. This same process could explain mysterious noises heard during the aurora borealis, or northern lights (SN: 8/9/14, p. 32). Like meteors, auroras have been known to emit radio wave bursts.

The planet KELT 9b is so hot — hotter than many stars — that it shatters gas giant temperature records, researchers report online June 5 in Nature.

This Jupiter-like exoplanet revolves around a star just 650 light-years away, locked in an orbit that keeps one side always facing its star. With blistering temps hovering at about 4,300o Celsius, the atmosphere on KELT 9b’s dayside is over 700 degrees hotter than the previous record-holder — and hot enough that atoms cannot bind together to form molecules.
“It’s like a star-planet hybrid,” says Drake Deming, a planetary scientist at the University of Maryland in College Park who was not involved in the research. “A kind of object we’ve never seen before.”

KELT 9b also boasts an unusual orbit, travelling around the poles of its star, rather than the equator, once every 36 hours. And radiation from KELT 9b’s host star is so intense that it blows the planet’s atmosphere out like a comet tail — and may eventually strip it away completely.

The planet is so bizarre that it took scientists nearly three years to convince themselves it was real, says Scott Gaudi of Ohio State University. Deming suspects KELT 9b is “the tip of the iceberg” for an undiscovered population of scalding-hot gas giants.

Jupiter was an early bloomer. New measurements of meteorite ages suggest that the giant planet’s core must have formed within the solar system’s first million years. If so, Jupiter’s presence could help explain why the inner planets are so small — and possibly even be responsible for Earth’s existence.

Previously, astronomers’ best constraints on Jupiter’s age came from simulations of how solar systems form in general. Gas giants like Jupiter grow by accreting gas from spinning disks of gas and dust around a young star. Those disks typically don’t last more than 10 million years, so astronomers inferred that Jupiter formed by the time that disk dissipated.
“Now we can use actual data from the solar system to show Jupiter formed even earlier,” says Thomas Kruijer, who did the research while at the University of Münster in Germany. Kruijer, now at Lawrence Livermore National Laboratory in California, and his team report Jupiter’s new age in the Proceedings of the National Academy of Sciences the week of June 12.

To study one of the biggest objects in the solar system, Kruijer and colleagues turned to some of the smallest: meteorites. Most meteorites come from the asteroid belt currently located between Mars and Jupiter but probably were born elsewhere.

Luckily, meteorites carry a signature of their birthplaces. The gas and dust disk that the planets formed from had different neighborhoods. Each had its own “zip code,” areas enriched in certain isotopes, or different masses of the same elements. Careful measurements of a meteorite’s isotopes can point to its home.

Kruijer and colleagues selected 19 samples of rare iron meteorites from the Natural History Museum in London and the Field Museum in Chicago. These rocks represent the metal cores of the first asteroid-like bodies to congeal as the solar system was forming.

The team dissolved about a gram of each sample in a solution of nitric acid and hydrochloric acid. “It smells terrible,” Kruijer says.
Then the researchers separated out the elements tungsten — a good tracer of both a meteorite’s age and birthplace — and molybdenum, another tracer of a meteorite’s home.

By measuring the relative amounts of molybdenum-94, molybdenum-95, tungsten-182 and tungsten-183, Kruijer and his team identified two distinct groups of meteorites. One group formed closer to the sun than Jupiter is today; the other formed farther from the sun.

The tungsten isotopes also showed that both groups existed at the same time, between about 1 million and 4 million years after the start of the solar system about 4.57 billion years ago (SN Online: 8/23/10). That means something must have kept them separated.

The most likely candidate is Jupiter, Kruijer says. His team’s calculations suggest that Jupiter’s core had probably grown to about 20 times the mass of the Earth in the solar system’s first million years, making it the oldest planet. Its presence would have created a gravitational barrier that kept the two meteorite neighborhoods segregated. Jupiter would then have continued growing at a slower rate for the next few billion years.

“I have high confidence that their data is excellent,” says cosmochemist Meenakshi Wadhwa of Arizona State University in Tempe. The suggestion that Jupiter held the different meteorites apart is “a little more speculative, but I buy it,” she adds.

Jupiter’s early entrance could also explain why the inner solar system lacks any planets larger than Earth. Many extrasolar planetary systems have large close-in planets, from rocky super-Earths (about two to 10 times the mass of Earth) to gassy mini-Neptunes or hot Jupiters. Astronomers have puzzled over why our solar system looks so different.

An early Jupiter’s gravity could have kept most of the planet-forming disk away from the sun, meaning there was less raw material for the inner planets. This picture is consistent with other work suggesting a young Jupiter wandered through the inner solar system and swept it clean (SN: 4/2/16, p.7), Kruijer says.

“Without Jupiter, we could have had Neptune where Earth is,” Kruijer says. “And if that’s the case, there would probably be no Earth.”

Children of Nso farmers in Cameroon know how to master the marshmallow test, which has tempted away the self-control of Western kids for decades.

In a direct comparison on this delayed gratification task, Cameroonian youngsters leave middle-class German children in the dust when challenged to resist a reachable treat while waiting for another goodie, a new study finds.

Of 76 Nso 4-year-olds, 53, or nearly 70 percent, waited 10 minutes for a second treat — a small local pastry called a puff-puff — without eating the puff-puff placed on a table in front of them, say psychologist Bettina Lamm of Osnabrück University in Germany and colleagues.
Only 35 of 125 German 4-year-olds, or 28 percent, successfully waited for their choice of a second lollipop or chocolate bar.

The study, which is the first to administer the marshmallow test to non-Western kids, shows that cultural styles of child raising can dramatically shift how self-control develops, Lamm’s team contends online June 6 in Child Development.

“The disparity between German and Nso cultures on the marshmallow test is huge,” says psychologist Ozlem Ayduk of the University of California, Berkeley. She concurs that parenting practices among Nso farmers may at least partly boost children’s ability to delay gratification.

Marshmallow tests conducted over the past 50 years have found that, as in the new study, a minority of children in Western countries manage to wait for a second treat without munching the first one (SN: 11/15/14, p. 28). And kids best able to wait out the test display academic and social advantages decades later (SN: 10/8/11, p. 12).

A Western cultural emphasis on raising children to be independent and to express what they want and how they feel presents challenges to self-control, Lamm says. Delaying a reward, as in the marshmallow test, stirs a frustrating feeling of powerlessness, her team proposes.
The kids in the new study were part of a long-term study of cultural differences in memory and learning. Age-appropriate assessments occurred three times during the kids’ first year of life and at ages 3 and 4. Only 4-year-olds took the marshmallow test. Among 63 of the German youngsters videotaped in play sessions with their mothers at age 9 months, those whose mothers were most lenient in letting them determine what to do displayed the least patience on the marshmallow test at age 4, the researchers say.

Researchers have long argued that “authoritative parenting,” marked by giving children freedom within specific limits, fosters self-control needed for academic and social success (SN: 8/19/89, p. 117). German kids who waited for a second treat had mothers who dealt with them authoritatively as 9-month-olds, Lamm says.

Nso mothers typically had an authoritative parenting style, keeping their kids close and training them to keep emotions in check and respect their elders, especially those high in a community’s pecking order. For 57 Nso kids recorded in play with their mothers at age 9 months, mothers consistently took the lead in organizing play activities.

Nso children’s self-control grew out of their mothers’ authoritarian, controlling parenting style, Lamm suspects.

Children also displayed cultural differences in how they tried to resist temptation during the marshmallow test. German kids tried to distract themselves while waiting for a second treat by moving about, turning around, singing, talking and even leaving the room. Nso youngsters waiting for a second treat exhibited little emotion and remained largely still. Eight of them fell asleep in their chairs.

Some previously tested Western children have rested their heads on the table and taken naps as a tactic to ignore available treats. But Nso kids appeared to zonk out spontaneously, slumping over in their chairs, Lamm says.

As a result of authoritarian parenting practices, Nso kids either squelch negative emotions or experience negative emotions in a different, more controllable way than Western peers do, she proposes.

Ayduk notes that it’s not clear whether Nso youngsters truly had greater self-control or if, true to farming community standards, they simply obeyed adults who asked them to wait for a second puff-puff, Ayduk adds.

While Nso values and parenting techniques generally characterize small-scale farming populations, especially in Africa, hunter-gatherers are another story, says anthropologist Barry Hewlett of Washington State University in Vancouver. Traditional hunter-gatherer groups value individual freedom and consider everyone to be relatively equal, regardless of age. Parents usually don’t tell their kids what to do, and children show little deference to parents and elders.

No hunter-gatherer kids have taken the marshmallow test. Hewlett expects most would scarf an available treat right away.

Get a grip. A new robotic gripping tool based on gecko feet can grab hold of floating objects in microgravity. The grippers could one day help robots move dangerous space junk to safer orbits or climb around the outside of space stations.

Most strategies for sticking don’t work in space. Chemical adhesives can’t withstand the wide range of temperatures, and suction doesn’t work in a vacuum.

Adhesives inspired by gecko feet — which use van der Waals forces to cling without feeling sticky (SN Online: 11/18/14) — could fit the bill, says Mark Cutkosky of Stanford University, whose team has been designing such stickers for more than a decade. Now his team has built robotic gripper “hands” that can grapple objects many times their size without pushing them away, the researchers report June 28 in Science Robotics.
The team first tested the grippers in the Robo-Dome, a giant air hockey table at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., where two 370-kilogram robots gently pushed each other around using a small square of gecko gripper.

Then last summer, Aaron Parness and Christine Fuller, of the Jet Propulsion Lab, and Hao Jiang of Stanford took the full gripper hand, which includes several patches of gripping material in a specific arrangement, on a microgravity flight in NASA’s Weightless Wonder aircraft. The team used the hand to grab and release a cube, cylinder and beach ball, which represented satellites, spent rockets or fuel tanks, and pressure vessels.

Gripper hands could be used to repair or move dead satellites, or help miniature satellites called CubeSats stick to larger spacecraft like barnacles, Parness says.

Hominid hubbub
In “Hominid roots may go back to Europe” (SN: 6/24/17, p. 9), Bruce Bower reported that the teeth of Graecopithecus, a chimp-sized primate that lived in southeastern Europe 7 million years ago, suggest it was a member of the human evolutionary family.

“Is it appropriate to use the terms ‘hominid’ and ‘ape’ as if the two are mutually exclusive categories?” asked online reader Tim Cliffe. “The distinction being made is between our clade in particular and all other apes. It seems to me that ‘hominids’ should be described as a subset of apes, not a separate category,” he wrote.
“Yes, hominids are apes,” Bower says. “The terminology gets pretty thick in evolutionary studies, so researchers (and journalists) use some shortcuts.”

Fossils of many ancient apes dating to between 25 million and 5 million years ago have been found, but the interest in this case is in a key transition to a particular kind of ape that walked upright and displayed various skeletal traits similar to traits unique to the human evolutionary family. “That’s why one source in the story, Bernard Wood, wonders whether Graecopithecus was an apelike hominid or a hominid-like ape,” Bower says. “But it’s important to remember that hominids diverged from other, ancestral apes. So did chimps.”

Science News defines “hominid” as a member of the human evolutionary family.

Laser, camera, action
The world’s fastest video camera films 5 trillion frames every second, Ashley Yeager reported in “A different kind of camera captures speedy actions” (SN: 6/24/17, p. 5). The camera works by flashing a laser at a subject and using a computer program to combine the still images into a video. Researchers tested the device by filming particles of light as the particles traveled a short distance.

Online reader JHoughton1 wondered if the researchers really filmed a light particle in their tests. “I thought light ‘sometimes behaves like a wave, sometimes like a particle,’ but that there isn’t really any particle that’s a particle in the usual sense. Is this really a picture of a ‘particle’ of light? A photon-as-ball-of-stuff?”

The camera captured the forward progression of a laser pulse, which is an ensemble of photons, Yeager says.

Photons themselves aren’t “balls of stuff” on quantum scales, says physics writer Emily Conover. All particles, including photons, are spread out in space, propagating like waves. “Only when scientists measure or observe a photon or any other particle do they find it in one place, like the ball of stuff that people typically imagine. I think in that sense, photons are about as tangible as any other quantum particle,” Conover says.

Bringing down the mucus house
Little-known sea animals called giant larvaceans can catch a lot of carbon in disposable mucus casings called “houses,” Susan Milius reported in “ ‘Mucus houses’ catch sea carbon fast” (SN: 6/10/17, p. 13).

Online reader Robert Stenton wondered what happens to mucus houses as they fall to the bottom of the ocean.

What happens to discarded houses isn’t yet clear, Milius says, though researchers have proposed that the houses might carry substantial portions of carbon to life on the sea bottom. And if bits of a house fall fast enough to reach great depths, the carbon could get trapped in water masses that move around the planet for centuries before surfacing. Bits drifting down slowly may be intercepted by microbes and other debris feeders and would not end up sequestered.

Correction
In “Human noises invade wilderness” (SN: 6/10/17, p. 14), Science News incorrectly reported that official wilderness areas in the United States do not allow livestock grazing. Grazing is permitted in protected wilderness areas at preprotection levels under the Wilderness Act of 1964, which created the National Preservation System.

Our view of the earliest flowers just bloomed. A new reconstruction, the most detailed to date, suggests the flowers were bisexual, with more than five female reproductive organs, or carpels, and more than 10 male reproductive organs, or stamen. Petallike structures, grouped in sets of three, surrounded the sex organs, researchers report August 1 in Nature Communications.

Flowering plants comprise roughly 90 percent of plants on Earth. Researchers think they evolved from a common ancestor that lived about 140 million years ago. But it has been hard to reconstruct the structure of such ancient blooms because so few fossils have been found.

In the new study, Hervé Sauquet of the Université Paris-Sud in Orsay, France, and colleagues combined models of flower evolution with a database of features for 792 species of flowering plants, and data from the fossil record. The new picture of ancient flowers suggests some blossoms lost their bisexuality with time. Also, modern blooms lost some of their whorls, the concentric layers of different flower parts. In some flowers, whorls dropped from at least four to two in petals and the leaflike structures at the base of a bloom, and from four to one in stamen, the team concludes. The finding suggests that natural selection pushed the plants to a less complex floral plan over time.